3 problems

E

Exogen

Member
Hello again,

as I said in the newbie forum, I am new, both to this forum, and to the Z4 (just bought an E86). I have had the car not even a month. The carfax is clean and its CPO but it has some issues. If I am going to encounter problems I would rather have them now, while I have the CPO.

My car is still under CPO for a year. It has 23k miles on it. However, I have already found some issues. I want to hear from your opinions, especially many of you who have more technical knowledge.

1. I noticed that at times when I was driving fast and would slow down quickly, when I would come to a stop I would feel a clunk. It felt like the transmission was slipping at 2nd to 1st. I have experienced this same problem in one of my old 3 series cars (E36). I brought it to the dealer and now they are replacing the transmission. I talked to a friend of mine at my job who is a mechanic. He used to work for Audi and thinks that the technology is similar. Bare in mind that I have an auto-manual (steptronic) transmission. He said there is this thing called adaption, where the transmission adapts to the drivers style. When new drivers come along sometimes there can be problems, and he said that the slip from 2-1 is a common problem (at least at Audi it was). He said that usually they clear the adaption and re-adapt it, although some dealerships (he used to work for Honda as well) will sometimes just replace the transmission entirely. His speculation is that is what they are doing at BMW. My service specialist was not specific enough, but I will inquire further. However I do not know that her knowledge will be as extensive as will satisfy me. Have any of you heard of this before, and what do you make of it?

2. I noticed one day that the heat gauge started overheating. I pulled over to a gas station before it could reach the redzone, let it cool down, and started the car up again. after that it returned to the normal middle position and I have not had a problem since. What are the common problems here?

3. This is probably the issue I am most concerned with now although it may be nothing (according to the dealer). When I start the car, for a few seconds it runs rough(rev spikes around 1k and fluctuating). After a few seconds it smooths out and it does not do that while driving or idle. The dealer says no fault codes have been activated and if it is a problem, to keep an eye on it and bring it in if a fault code comes up. My service specialist suspects that this may normal. My friend from work (the mechanic) thinks it could be dirty fuel injectors because he thinks that the fuel injectors on the Z4 are closer to the cylinders. He is just speculating but he thinks they might be prone to get dirty more and harder to clean.

Do any of you all have this same issue when the car starts up? If this is normal then this should be a the same for everyone. Anyone have any ideas? Thanks.
 
Hi and welcome Exogen

Can't help on the first 2 problems, but I have experienced similar issues with rough idling for the first 10 secs, see this thread http://www.z4-forum.com/forum/viewtopic.php?t=46501 my zed was also a low mileage model.

Luckily my zed was covered by AUC warranty as BMW spent about $5k trying the cure it. Mine used to trigger a fault code, however the code only triggered if driven for short trips of about 10 miles a day over a 5 day period. A code was never triggered if driven over long distances. BMW managed to stop an error code being triggered, and for the past 12 weeks the zed has been error code free. I still get the odd rough idle if the engine is warm, however it only lasts 6 secs and doesn't effect the performace and no error code or management light issues, so can live with it.
 
Welcome!

I've not heard of many transmission problems. You say when you slow to a stop it slips from 2 to 1. I'm not following. Wouldn't one expect it to drop to 1st when you stop? Regardless, it shouldn't clunk, and I doubt adaptation has anything to do with clunking.

Funny you had a spurious overheating issue, I just experienced the exact same thing! Overheated, and on further investigation could not find anything wrong, and now it agian flies up steep mountain grades without a hint of getting hot. I did find some air in the system, but I'm not sure it was there all along or I introduced it during my investigations.

I think I may have had fluctuating revs on start up once or twice. Rare enough that I may be recollecting a different car. I don't think it's anything to worry about if it rights itself quickly and no trouble codes are thrown.
 
Bcworkz,

What I mean when I say "from 2-1" is when I am stopping rapidly, after going very fast, as the car has stopped, I here a clunk. It feels like when the transmission is downshifting that it hesitates and fully shifts at the end, once I have stopped completely. In any case, they are putting a new transmission in so I guess it doesn't matter anymore.

the rev issue is only when I first start the car. So does your car fluctuate (run rough) EVERY time you start it up, after it has been sitting for a while? Mine does. The dealer thinks it MAY be normal, but I have not received an absolute confirmation of this.

that's crazy that you have had an overheating problem as well. It is the damndest thing; It did it that one time, and then never again.

Swiftly,

I will look into that thread, thanks! :)
 
No, the rev thing is very rare for me, so I can't recall the specifics. It's certainly not normal, but I'm not sure it's anything to worry about if it settles fairly quickly. It's actually rather surprising modern engines start quickly and run perfectly from a cold start. It's all because of a slew of high tech sensors, with out that kind of management, every cold engine would run far worse than you are experiencing.

I'm not ready to proclaim my overheating is one time only, I've only had it out twice since then, I still don't trust that it's really a one off. Your experience is sort of reassuring that I may not be totally stranded somewhere.
 
Bcworkz,

yes the overheating was weird but we will see if it does it again.

Looking at the thread that Swiftly posted, the rev issue looks just like the videos he posted of the issue he was having on startup - Exactly the same, minus any fault codes. That's the only difference. Why do you say it isn't normal? Does yours do it?

I would really be interested to know what others experience here is, do all Z4's on startup run rough for 20-30 seconds and then level out? I can feel the vibration from the engine when it does that; doesn't seem like it should do that, but what do I know.
 
I say it's not normal because mine does not usually do it and and after spending a lot of time on this forum over a rather long period, it's just not mentioned that often. It's just my opinion, I'm in no way any kind of official spokesman for what the general consensus thinks.

Regardless what I think, it's obviously bothering you. It's at least worth doing some cursory investigation, like checking for air, vacuum, and exhaust leaks. It's worth at least cleaning the MAF sensor, and maybe the injectors. On M54s also consider cleaning the ICV and throttle body. Also try changing fuel brands for a while. Beyond those things, you'll probably need to wait until it gets bad enough to throw a code or two.
 
Update,

The dealer emailed me and told me that the transmission has not yet arrived, and it might take as long as the 10th! :headbang: :cry: so I'm going to be sitting here, with their loaner vihicle, a 328Xi or something :tumbleweed:

As far as the idle thing, they told me that the shop foreman will be looking at it and if necessary they will reach out to the region engineer.

The process continues...
 
At least the dealer is responsive to your concerns, this is much more than can be said for most of them.
 
So I have my car back now.

The new Transmission is GREAT!!!

The overheating issue has never returned from that one day. Who knows what it was or if/when it will come back, but I will take it from then.

as for the rough idle on start-up, I talked to one of the apparent BMW "gurus," and he told me that it is normal for the size of the engine (3.0si) and that its not a problem, especially considering that it only lasts for all of about 10 seconds or so.

I had a friend of mine who is a mechanics bring over his diagnostic equipment and there were no codes whatsoever, so the dealer seems to be correct here.
 
Exogen said:
So I have my car back now.

The new Transmission is GREAT!!!

The overheating issue has never returned from that one day. Who knows what it was or if/when it will come back, but I will take it from then.

as for the rough idle on start-up, I talked to one of the apparent BMW "gurus," and he told me that it is normal for the size of the engine (3.0si) and that its not a problem, especially considering that it only lasts for all of about 10 seconds or so.

I had a friend of mine who is a mechanics bring over his diagnostic equipment and there were no codes whatsoever, so the dealer seems to be correct here.
Click to expand...
Great result! :thumbsup:
 
Agreed, nice one :thumbsup:

Didn't see this before, but when I start my car from cold it runs at slightly higher revs - about 1000 like yours - for a short while. Then settles back to 650-700. Sometimes sounds a bit rough but not all the time, not loud or tappety enough for me to worry, and it quickly goes when the revs drop. Normal I'd say - with a car that is fairly new to you I guess it is natural to be more sensitive to unfamiliar noises or behaviour.
 
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